CVE-2024-53066

In the Linux kernel, the following vulnerability has been resolved:

nfs: Fix KMSAN warning in decode_getfattr_attrs()

Fix the following KMSAN warning:

CPU: 1 UID: 0 PID: 7651 Comm: cp Tainted: G B

Tainted: [B]=BAD_PAGE

Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)

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BUG: KMSAN: uninit-value in decode_getfattr_attrs+0x2d6d/0x2f90

decode_getfattr_attrs+0x2d6d/0x2f90

decode_getfattr_generic+0x806/0xb00

nfs4_xdr_dec_getattr+0x1de/0x240

rpcauth_unwrap_resp_decode+0xab/0x100

rpcauth_unwrap_resp+0x95/0xc0

call_decode+0x4ff/0xb50

__rpc_execute+0x57b/0x19d0

rpc_execute+0x368/0x5e0

rpc_run_task+0xcfe/0xee0

nfs4_proc_getattr+0x5b5/0x990

__nfs_revalidate_inode+0x477/0xd00

nfs_access_get_cached+0x1021/0x1cc0

nfs_do_access+0x9f/0xae0

nfs_permission+0x1e4/0x8c0

inode_permission+0x356/0x6c0

link_path_walk+0x958/0x1330

path_lookupat+0xce/0x6b0

filename_lookup+0x23e/0x770

vfs_statx+0xe7/0x970

vfs_fstatat+0x1f2/0x2c0

__se_sys_newfstatat+0x67/0x880

__x64_sys_newfstatat+0xbd/0x120

x64_sys_call+0x1826/0x3cf0

do_syscall_64+0xd0/0x1b0

entry_SYSCALL_64_after_hwframe+0x77/0x7f

The KMSAN warning is triggered in decode_getfattr_attrs(), when calling

decode_attr_mdsthreshold(). It appears that fattr->mdsthreshold is not

initialized.

Fix the issue by initializing fattr->mdsthreshold to NULL in

nfs_fattr_init().